Roundtable on Urban Ecohydrology Science and Practice

Roundtable on Urban Ecohydrology
Science and Practice
July 24th, 2012
Drexel University
Philadelphia, PA
Welcome to Drexel University!
Charles N Haas, PhD, BCEEM, F ASCE, F AAAS, F
AAM, F IWA, F SRA
LD Betz Professor of Environmental Engineering
Head - Dept. of Civil, Architectural & Environmental
Engineering, Drexel University
Overview of Workshop Goals and
Specific Activities
Phillip Rodbell
US Forest Service
Urban and Community Forestry
Workshop Goals
• Explore applied research opportunities in the
specialized field of urban ecohydrology
• Engage stakeholders in dialogue regarding the
use of green infrastructure for stormwater
management & climate change adaptation
• Foster dialogue between researchers and
practitioners
• Generate urban ecohydrology research
priorities list
Agenda for the day
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9:30 – 10:10
10:10 – 11:50
12:00 – 1:00
1:00 – 1:20
1:20 – 1:30
1:20 – 3:00
3:00 – 3:30
3:30 – 4:00
Introductory presentations
Technical presentations
Lunch a-”roundtables”
Strawperson presentation
Roundtable instructions
Roundtable activities
Report back
Next Steps, Survey
Welcome from
CCRUN!
Linda E. Sohl
CCSR/GISS at Columbia University
Consortium for Climate Risk in
the Urban Northeast (CCRUN)
A NOAA Regional Integrated Sciences and Assessments (RISA) Project
Boston
New York
Philadelphia
Urban Eco-Hydrology Roundtable
July 24, 2012
Drexel University
Philadelphia, Pennsylvania
7
Mission
CCRUN conducts stakeholder-driven research that
reduces climate-related vulnerability and advances
opportunities for adaptation in the urban Northeast
Storm damage in Westchester County, NY, March 12-15, 2010.
Source: James Estrin / The New York Times
Striped bass fishing in Boston Harbor.
Source: Capt. Bill Smith / FishBoston.com
8
Overview
• Five year project (2010-2015)
• Geographic scope includes the
Boston – New York –
Philadelphia urban corridor
• Focus on vulnerable
populations and infrastructure
• Watersheds, Coastal Zones, and
Health sectors
9
Project Sphere
Water
Coasts
Health
Climate
Opportunities • Vulnerability •
Adaptation • Management
10
Objectives
• Develop risk assessments of weather, climate
variability, and climate change tailored to urban
stakeholder needs
• Integrate interdisciplinary research with stakeholder
management of climate risks in the areas of water,
health, and coastal zones
• Create and evaluate tools, training activities, and
outreach efforts to support enhanced stakeholder
capacity to understand climate risks and develop
adaptation strategies
Green Infrastructure as a
Climate Adaptation
Strategy
Franco Montalto
Dept. of Civil, Architectural, & Environmental Engineering
Drexel Engineering Cities Initiative (DECI)
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INFRASTRUCTURE AND LAND USE
People
Ecosystems
What are the impacts of our action?
Local environmental conditions
(on land, in air, in water)
How are we impacted?
Global climate system
(historical or changed)
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What is Green Infrastructure?
Strategically placed:
• Impervious surface removal efforts
• Stormwater diversion, storage, &
use projects
• Urban natural landscape
restoration efforts
Stakeholder interest:
• Cost-effective means to manage
urban watersheds and meet waterrelated infrastructure needs
• Contribution to urban
sustainability goals
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Relevant Research Questions
• How will infrastructure and land use changes
brought about by GI management plans alter
environmental conditions (under all possible
climatic conditions)?
• How more or less vulnerable to climatic
variability will people and ecosystems be with GI
in place?
• What scale issues are relevant (space and time)?
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Ecohydrology
•
Peter Eagleson – seminal papers, 1970s
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The functional interrelationships between hydrology
and biota at the catchment scale (Zalewski 2000)
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The hydrologic mechanisms that underlie ecological
patterns and processes (Rodriquez-Iturbe 2000)
Urban Ecohydrology
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How relevant/transferable are traditional
ecohydrology research results to engineered urban
environments?
Urban ecosystems characterized
by:
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Habitat patches
Hard physical boundaries
Disturbed, imported soils
Installed plants
Urban climates
GI Monitoring Network
The Sustainable Water Resource Engineering Lab at Drexel University
New York City sites
Philadelphia sites
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Bioretention “Greenstreet” Monitoring Setup
Full climate station &
solar power station
Nashville & 116th Street, Queens, NY
Overflow to sewer
with Thel-mar weir
Groundwater
well (10m)
Sap flux sensors
(in trees)
Slotted
shallow well
(1m)
Inlet from street
with flume, stilling
well & and flow
diverter box
ISCO water
quality sampler
and inline flow
meter
Weighing lysimeter
with vertically
distributed soil
moisture and
tensiometer arrays
Data
logger
w/cell
modem
Soil
moisture
arrays
(external to
lysimeter)
How might GI
modify the
microclimate of
the urban spaces
that surround it?
Image: Scott Jeffers
How much precipitation can be attenuated in new urban
canopies?
2.6 million cubic meters per year
= 687 million gallons per year
Citywide volume of rainfall intercepted by
240,000 street trees > annual volume of
CSOs offset by grey infrastructure….
(though doesn’t mean these trees will
reduce CSOs
– depends
meters
per
year on spatial
distribution)
2.6 million cubic
= 687 million gallons per year
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Weighing Lysimeters
(evapotranspirometers)
Weighing Lysimeters
(evapotranspirometers)
Green Roof –
Fieldston
Sedum species
Bioretention Area
(irrigated) –
Nashville (right)
Juncus effusus
Urban Park –
Alley Pond (left)
Mixed natives
Bioretention Area
(un-irrigated) –
Colfax (left)
Aster dumosus
How different is ET in different urban green spaces?
Lysimeter Measured Actual Evapotranspiration
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Urban Park - Alley Pond
Bioretention Area - Colfax
Green Roof - Fieldston
Bioretention Area - Nashville
Evapotranspiration (mm/day)
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8
7
6
5
4
3
2
1
0
Jun09
Oct09
Feb10
Jun10
Oct10
DiGiovanni et al (in preparation)
Feb11
Jun11
Oct11
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How different are soil
moisture patterns in GI
systems from natural
landscapes?
Image: Ryan Asensio
Are classical equations used to predict ET valid in the urban
environment?
Green Roof - Fieldston
Ratio of AET:RET vs. Volumetric Water Content
1.5
ActualET:ReferenceET
1.25
1
𝐾𝑐
0.75
0.5
0.25
0
0.05
0.1
0.15
0.2
0.25
3
0.3
3
Media Volumetric Water Content m /m
DiGiovanni et al (in preparation)
0.35
0.4
Infiltration Rate (cm/min)
How different are infiltration rates from different urban green
spaces? How do these compare to rainfall intensities?
Fig. 12
Alizadehtazi et al (2012, forthcoming)
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How much more resilient to drought can we become
if we use urban stormwater productively?
Rostad and Montalto (2012)
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Can GI offset CO2 emissions?
Catalano de sousa et al (accepted)
Can GI offset CO2 emissions?
Catalano de sousa et al (accepted)
Concluding remarks
• We are currently changing urban ecosystems
in unprecedented new ways
• The flow of water through urban ecosystems
determines urban environmental quality and
resilience to stressors (like climate change)
• Adaptive management is only possible if we
are systematically documenting the effects of
what we are doing and developing improved
predictive capabilities.
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Ecohydrological principles: Green
infrastructure meets stormwater
engineering
Ken Belt
US Forest Service
Urban and Community Forestry
Technical presentations
What decisions are practitioners making and
what research is needed?
Lunch & Afternoon logistics